He is the adopted son of Genkaku, and step brother to Nanami. As a young boy he was made fun of because he was an orphan, and spent all of his time with Nanami and his best friend, Jowy. As they reached their teens, he and Jowy joined the Unicorn Brigade of the Highland Army; where his skill in martial arts, taught to him by Genkaku, made him a formidable fighter.

After the Highland Army massacred the Unicorn Brigade and blamed it on Jowston's Army, he escaped and joined Viktor's mercenaries. Eventually, he ended up becoming the leader of the Dunan Unification movement, and led them to victory. After the Dunan Unification War, he disappeared along with the former Highland King, Jowy Blight (Atreides) and his sister, Nanami. He wears a circlet and shoulder pads that were given to him as a young boy by Genkaku, and fights with a pair of tonfas. - Blue Moon

Gameplay Information for Suikoden II

How to Recruit: You control Riou from the beginning. If you enter a different name at the beginning, that will be his name.